Heater



FIG. 1 is an upper perspective view of a heater, showing our new design;

FIG. 2 is a lower perspective view of the heater shown in FIG. 1 ;

FIG. 3 is a side view of the heater shown in FIG. 1 , the opposite side being a mirror image thereof;

FIG. 4 is a front view of the heater shown in FIG. 1 , the rear view being a mirror image thereof;

FIG. 5 is a top view of the heater shown in FIG. 1 ; and,

FIG. 6 is bottom view of the heater shown in FIG. 1 .

The broken lines in the figures depict environmental subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a heater, as shown and described. 